CODEWITHSUNDEEP
rustblockchainsmartcontractsnearprotocol
mattdlockyer
mattdlockyer

Reputation: 7314

NEAR Protocol Rust contracts - what's the difference between near-sdk-rs data structures and std ones?

In Rust we have many data structures available in the standard library. NEAR Protocol has some optimized data structures in near-api-rs, but what are the main differences?

Upvotes: 1

Views: 261

Answers (1)

mattdlockyer
mattdlockyer

Reputation: 7314

Evgeny Kuzyakov (a Near protocol engineer) answered in Discord:

If you talking about LookupMap vs HashMap then the difference is LookupMap is stored in the trie, while HashMap is stored in memory.

When a method on a contract is called, the contract reads and deserializes the main struct from the storage trie. If it contains a HashMap then all records of this map will be read and deserialized. If it contains a LookupMap then only the key_prefix will be read and deserialized, so it's cheaper from gas perspective. But every time you access a key/value from a LookupMap you have to read and deserialize it from the trie.

Upvotes: 3

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